Apparatus and method to detect foundation movement

ABSTRACT

An apparatus for monitoring the movement of a foundation may include an elevation sensor to detect changes in elevation of the foundation and positioned on the foundation to broadcast a signal responsive to the movement of the foundation; and a receiver to receive the signal responsive to the movement of the foundation and positioned off the foundation to provide a absolute measurement of the movement of the foundation.

This application is a continuation application of U.S. application Ser.No. 16/425,522, filed May 29, 2019, the entirety of which is herebyincorporated by reference.

FIELD OF THE INVENTION

The present invention relates to an apparatus and method to detectfoundation movement or stability for in particular, reinforced concretefoundations like concrete pier foundations.

BACKGROUND

In the construction industry, there has been significant effort overtime to reduce the impact that soil movement has on the foundation andthe edifice that is constructed upon it. Even though foundations havebeen built for centuries, a foundation that remains flat or stable overlong periods of time has been expensive to achieve and eludes mostbuyers. A home foundation that stays flat or stable forever has eludedmany in the industry.

Technologies to repair cracked foundations are well known in theconstruction industry and offer varying degrees of success and economicviability. The foundation repair industry is common for having employeeswith little or no knowledge in the field who are conducting theevaluation of the home. There is currently no credible way to determineif a foundation built on soil which is suspected of movement hasactually moved relative to its initial “as built” condition. Elevationmaps taken of a building can be misleading because the soil changesseasonally and the flooring surfaces rarely remain flat over the usefullife span of a building. It is difficult to be certain about thepresence or absence of modifications to the structure. This results inseasonal fluctuations in foundation heave or sag that can be hard toseparate from a true permanent deformation. Soils of varying propertiesthat are native or brought in during the construction process likewisecreate a problem that has to be dealt with by the engineer designing thefoundation, the company constructing on said soils, the developer whobought the land, the insurance company who may have an insurance policyagainst foundation movement, and all property owners.

Foundation inspectors and engineers use relative floor elevations todetermine if a foundation is failing. This is currently done by using adigital manometer machine (a so-called computer level) that is placed inthe middle of the foundation of the home/building. This is the then usedas the base reference point for the foundation measurements. The digitalmanometer machine is then placed around the foundation, and the digitalmanometer machine will register the relative foundation heightdifferences to the center reference point as a negative or positiveelevation difference. Most engineers and or inspectors use a negative−1.0 inch or more from the center reference point to determine that thefoundation needs piers or adjustments of existing piers if they exist.

This method, as described above of determining that a foundation isfailing, is only correct approximately 30 percent of the time.Foundations that are failing almost always have seasonal cycling of thefoundation elevation. If an engineer only takes one set of elevationsduring the wet season a foundation may be level but still unstable andin need of repair. Additionally, the relative elevations are almostalways taken from the center of the foundation of the home. If thecenter of the foundation of the home/building is not stable or isdynamic, the unstable center of the foundation will cause all the otherelevation measurements to be incorrect.

SUMMARY

The present invention positions a transmitter/receiver external to thefoundation (a non-foundation location) for example on a deep driven pierto provide a stable platform in the yard or on a nearby fixed staticpoint to be used as a frame of reference. Thus, the measurements thatare received by the transmitter/receiver are independent of movement ofthe foundation and not biased by the movement of the foundation of thehome/building. This transmitter/receiver communicates with transmittersassociated with the elevation sensors on the foundation inside the hometo determine the movement of the foundation from a fixed/stablereference point rather than a dynamic (moving) reference point. Thesetransmitters/receivers can be linked to central monitoring station suchas an application on a phone or a home computer and provide weekly,monthly or yearly foundation elevations and to would be able to alsodetermine with substantially 100 percent accuracy how much, where, whatand in which direction the foundation is shifting. Thus, a relativemeasurement between the elevation sensor and the transmitter/receiver isavoided and an absolute measurement between the elevation sensor and thetransmitter/receiver is achieved.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention may be understood by reference to the followingdescription taken in conjunction with the accompanying drawings, inwhich, like reference numerals identify like elements, and in which:

FIG. 1 illustrates a top view of a foundation with sensors mounted;

FIG. 2 illustrates a side view of a portion of the foundation and asingle sensor mounted;

FIG. 3 illustrates a front view of the sensor system of the presentinvention;

FIG. 4 illustrates a side view of an interior wall of the presentinvention;

FIG. 5 illustrates a top view of a wireless sensor of the presentinvention;

FIG. 6 illustrates a side view of the transmitter/receiver of thepresent invention;

FIG. 7 illustrates a front view of a control device of the presentinvention

DETAILED DESCRIPTION

FIG. 1 illustrates a foundation 102 for a building such as a house orcommercial dwelling/building. Furthermore, the foundation 102 may be fora device such as a windmill power generator. While FIG. 1 illustrates afoundation 102 which is substantially a multitude of rectangles, thefoundation 102 may include curved surfaces. FIG. 1 additionallyillustrates a multitude of elevation sensors 104 which can detectchanges in vertical elevation from a predetermined initial position ofthe sensor 104 to a raised or lowered position of the elevation sensor104 and to broadcast a signal corresponding to the change in verticalelevation to a central transmitter/receiver 106. The centraltransmitter/receiver 106 may be external to the foundation 102 and maybe positioned at a stable location such as on a deep driven pier toprovide a stable platform in the yard or on a nearby fixed static pointto be used as a frame of reference The sensor 104 may be wirelesslyconnected to the central transmitter/receiver 106 or may be wired orotherwise connected to the central transmitter/receiver 106. Thetransmitter/receiver 106 is not positioned on the foundation 102 butmounted exterior to the foundation on a deep driven pier to provide astable platform in the yard or on a nearby fixed static point to be usedas a frame of reference. The transmitter/receiver 106 receives theelevation signal from the elevation sensors 104 and sends a secondsignal to a central monitoring station 120 where the decision may bemade to correct the movement of the foundation 102.

The sensors 104 may be positioned at a multitude of positions on thefoundation 102. Sensors 104 may be positioned at corners of thefoundation 102 as shown as position 1, position 2, position 3, positionnumber 4, position 5, position 6, position 8, position 9, position 10,position 11, position 12, and position 13. However, sensors 104 may bepositioned along sides of the foundation as shown as position 14,position 15 and position 7. Furthermore, sensors 104 may be positionedat interior portions of the foundation as shown as position 16 andposition 17.

The central transmitter/receiver 106 may be positioned/mounted on a deepdriven pier to provide a stable platform in the yard or on a nearbyfixed static point to be used as a frame of reference and receives thebroadcast signals from the elevation sensors 104 (an example would bethe use of Bluetooth or Wi-Fi or the transmitter/receiver 106 may bedirectly connected to a cell phone tower) which correspond to the changein elevation of each of the elevation sensors 104 and when a signalindicates that the elevation change from the elevation sensors 104reaches a threshold predetermined value, the transmitter/receiver 106which may be positioned on a deep driven pier to provide a stableplatform in the yard or on a nearby fixed static point to be used as aframe of reference is activated and transmits a signal to a remotelocation such as a central station 132 to receive wireless signals fromthe transmitter/receiver 106 to indicate the foundation 102 has shiftedand may be in danger of damage to the foundation 102. Thetransmitter/receiver 106 is not positioned on the foundation 102 but maybe positioned external to the foundation 102 which may be on a deepdriven pier to provide a stable platform in the yard or on a nearbyfixed static point to be used as a frame of reference in order toeliminate (is independent from) any movement of the transmitter/receiver106 due to the movement of the foundation 102.

Alternatively, the transmitter/receiver 106 may continuously receivesignals from sensors 104 or alternatively the transmitter/receiver 106may be activated to interrogate the sensor 104 so that the sensor 104 isactivated to transmit a current elevation signal to thetransmitter/receiver 106.

FIG. 2 illustrates a portion of the foundation 102 which may include atop surface 108 which may be opposed to a bottom surface 112 and whichmay be connected to a side surface 110. FIG. 2 additionally illustratesan elevation sensor 104 which may be mounted on the top surface 108 andillustrates a building wall 114 which may be an interior wall or anexterior wall.

FIG. 3 illustrates a first building 116, a second building 118 and thecentral transmitter/receiver 106 which may be positioned on a deepdriven pier to provide a stable platform in the yard or on a nearbyfixed static point to be used as a frame of reference and which mayreceive first signals 122 transmitted from the first elevation sensors104 from the first building 116 and/or the second signals 124transmitted from the second elevation sensors 104 from the secondbuilding 118 either simultaneously or non-simultaneously.

The transmitter/receiver 106 may be positioned in a housing 126 and mayinclude shaft 128 to mount the housing 126 and may be mounted on a pier130 which may extend into a substantially unmovable location such asbedrock.

FIG. 4 illustrates an exploded view of a building wall 114 which may becovered with an appropriate material such as wallboard 134 which may beattached to building studs 134 which in turn may be secured to thefoundation 102. The elevation sensor 104 may be mounted on thefoundation 102 in order to measure changes in the vertical height of thefoundation 102.

FIG. 5 illustrates a top view of the elevation sensor 104 which ispositioned independently of the foundation 102.

FIG. 6 illustrates a front view of the transmitter/receiver 106 whichmay be positioned on a deep driven pier to provide a stable platform inthe yard or on a nearby fixed static point to be used as a frame ofreference to receive signals from the elevation sensor 104 and totransmit signals to the central monitoring station 120 as shown in FIG.7 which may be a handheld device such as a smart device, tablet orphone. The monitoring station 120 may transmit signals to thetransmitter-receiver 106 to control the transmitter/receiver 106.

While the invention is susceptible to various modifications andalternative forms, specific embodiments thereof have been shown by wayof example in the drawings and are herein described in detail. It shouldbe understood, however, that the description herein of specificembodiments is not intended to limit the invention to the particularforms disclosed.

What is claimed is:
 1. A system for monitoring movement of a foundation,comprising: a receiver disposed on a platform off of the foundation, theplatform stable relative to the foundation and comprising a frame ofreference, wherein the receiver further comprises a transmitter; anelevation sensor disposed on the foundation and configured to broadcastto the receiver a plurality of first signals representing a plurality ofelevation measurements of the elevation sensor, wherein the receiver isconfigured to generate, based on the plurality of first signals and theframe of reference, a plurality of second signals representing aplurality of elevation changes of the elevation sensor over time,relative to the frame of reference; and a central station configured toreceive, from the transmitter, the plurality of second signals.
 2. Thesystem of claim 1, wherein the plurality of elevation changes aremeasured at a time period selected from the group consisting of: weekly,monthly, yearly, and combinations thereof.
 3. The system of claim 1,wherein the central station comprises a handheld device.
 4. The systemof claim 3, wherein the handheld device is a smart phone.
 5. The systemof claim 3, wherein the handheld device is a tablet.
 6. The system ofclaim 1, wherein the receiver is wirelessly connected to the elevationsensor.
 7. The system of claim 1, wherein the elevation sensor isdirectly mounted on the foundation.
 8. The system of claim 1, whereinthe elevation sensor is mounted at a corner of the foundation.
 9. Thesystem of claim 1, wherein the elevation sensor is mounted at a side ofthe foundation.
 10. The system of claim 1, wherein the elevation sensoris mounted on an interior of the foundation.
 11. A method comprising:placing a receiver on a platform off of a foundation of a building, theplatform stable relative to the foundation and comprising a frame ofreference; placing an elevation sensor on the foundation; broadcasting,from the elevation sensor to the receiver, a first signal representingan elevation measurement of the elevation sensor; generating, by thereceiver based on the first signal and the frame of reference, a secondsignal representing an elevation change of the elevation sensor,relative to the frame of reference; transmitting the second signal to acentral station; repeating broadcasting, generating, and transmitting ata time interval to generate a plurality of second signals, wherein theplurality of second signals represents a plurality of differentelevation measurements of the elevation sensor; and transmitting, to thecentral station, the plurality of different elevation measurements ofthe elevation sensor.
 12. The method of claim 11, further comprising:correcting movement of the foundation using the plurality of secondsignals.
 13. The method of claim 11, further comprising: correctingmovement of the foundation using the plurality of different elevationmeasurements of the elevation sensor.
 14. The method of claim 11,wherein the time interval is selected from the group consisting ofweekly, monthly, yearly, and combinations thereof.
 15. The method ofclaim 11, wherein placing the elevation sensor on the foundationcomprises at least one of the group consisting of: placing the elevationsensor directly on the foundation; placing the elevation sensor within awall of the building on the foundation; placing the elevation sensor ata corner of the foundation; placing the elevation sensor at a side ofthe foundation; placing the elevation sensor on an interior of thefoundation.
 16. The method of claim 11, further comprising: placing theplatform outside of the foundation.
 17. The method of claim 16, whereinplacing the platform comprises driving a pier into bedrock.
 18. A methodcomprising: receiving, at a receiver, a first signal from an elevationsensor disposed on a foundation of a building, wherein the receiver isdisposed on a platform that comprises a stable frame of referencerelative to the foundation, wherein the first signal comprises anelevation measurement taken by the elevation sensor; determining, by thereceiver using the first signal and the stable frame of reference, achange in elevation of the elevation sensor; transmitting, by thereceiver, the change in elevation to a central station; repeatingreceiving, determining, and transmitting at a time interval to generatea plurality of changes in elevation; and transmitting, to the centralstation, the plurality of changes in elevation of the elevation sensor.19. The method of claim 18, further comprising: correcting movement ofthe foundation using the change in elevation.
 20. The method of claim18, further comprising: correcting movement of the foundation using theplurality of changes in elevation of the elevation sensor.